Spanish-Haitian War

The Spanish-Haitian War was fought from 13 May to 25 August 1864 when Spain invaded and annexed Haiti. The Spanish, who had recently reconquered the Dominican Republic, proceeded to completely restore their control over Hispaniola by conquering Haiti.

Background
In 1863, the Spanish government, which sought to counter France's growing power in the Americas (especially Mexico), occupied the Dominican Republic and restored the Captaincy General of Santo Domingo. Spanish troops from Cuba and Puerto Rico were sent to occupy the Dominican city of La Vega and the capital of Santo Domingo, and, by 1864, they numbered almost 21,000 men.

The Spanish government was pleased with the news of the reconquest of the Dominican Republic, and the conservative Liberal Union government supported the full reconquest of Hispaniola through the annexation of neighboring Haiti. Haiti, a country founded through a slave revolution, was entirely black and Francophone, and its Afro-Antillean population shared little in common with the Afro-Caribbean population of Santo Domingo. However, the Spanish planned to first annex Haiti and then attract immigrants to the island, as well as build a naval base at Port-au-Prince for use in further interventions in the Americas (just as they had done in Colombia in 1862).

War
The Spanish government fabricated claims that Haiti was preparing to invade Santo Domingo and reconquer the island as a whole, and, on 13 May 1864, Spain declared war on Haiti. The 25,000-strong Spanish army crossed the border from La Vega in Santo Domingo to Port-au-Prince in Haiti, where they defeated Nicholas Geffrard's smaller, 9,000-strong Haitian army; however, the Spanish losses of 3,162 men surpassed the Haitian losses of 2,883 men. The Haitian army retreated from its capital to Cap-Haitien, where Oreste Soulouque took command of the remaining forces. Soulouque did nothing as the Spanish occupied Port-au-Prince, and, on 20 August 1864, the Spanish defeated Soulouque's army at Cap-Haitien, this time wiping out the remaining 7,158 Haitian troops with just 775 losses. The Spanish proceeded to occupy Cap-Haitien, and, on 25 August, the United Kingdom - Haiti's ally - gave the Spanish permission to annex the occupied country. The Spanish thus restored their control over Hispaniola, although the Spanish were unable to spread slavery to the island, whose former countries had already abolished the practice.